Methods of fabricating components for microelectronic devices are described herein. For example, one embodiment is directed toward a method of fabricating a memory cell on a workpiece having a substrate, a plurality of active areas in the substrate, and a dielectric layer over the active areas. Bit line contact openings can be formed in the dielectric layer over first portions of the active areas and cell plug openings over second portions of the active areas. A first conductive material is deposited into the bit line contact openings to form bit line contacts and into the cell plug openings to form cell plugs. A conductive line is formed in a trench in the substrate. Dielectric features can electrically insulate the conductive line.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A method of fabricating a component for a microelectronic device having a workpiece including a substrate, a plurality of active areas in the substrate, a plurality of shallow trench isolation structures in the substrate between active areas, a dielectric layer over the active areas, contacts in the dielectric layer contacting a first portion of the active areas and a portion of an adjacent shallow trench isolation structures, and conductors in the dielectric layer contacting a second portion of the active areas, the method comprising: embedding an elongated conductive line in a trench extending through an upper portion of the contacts and sections of the dielectric layer between the contacts, the elongated conductive line being superimposed over portions of the shallow trench isolation structures but not over the first portion of the active areas; and electrically insulating the conductive line from the conductors by providing dielectric spacers in the trench between the conductive line and the conductors.
2. The method of claim 1 wherein embedding the elongated conductive line comprises using only two photolithographic and etching processes including (a) a first photolithographic and etching process to construct openings corresponding to the contacts and the conductors, and (b) a second photolithographic and etching process to form the trench through the upper portion the contacts.
3. The method of claim 1 wherein the trench includes first and second sidewalls, and wherein embedding the elongated conductive line comprises embedding the conductive line in the dielectric layer so that the first and second sidewalls of the trench are between the conductors.
4. The method of claim 1 wherein the trench includes first and second sidewalls, and wherein embedding the elongated conductive line comprises embedding the conductive line in the dielectric layer and the contacts so that (a) the first and second sidewalls of the trench are between conductors, and (b) the conductive line has a top surface at least substantially coplanar with a top surface of the dielectric layer.
5. The method of claim 1 wherein embedding the elongated conductive line comprises: constructing contact openings and conductor openings comprises (a) a first photolithographic process that forms a pattern on the dielectric layer having apertures corresponding to a desired arrangement of the contact openings, and (b) etching the dielectric layer to form the contact openings; and forming the trench comprises (a) a second photolithographic process that forms an elongated slot corresponding to a location for the trench, and (b) etching the trench in the upper portions of the contacts and portions of the dielectric layer between the contacts.
6. The method of claim 1 wherein the trench includes first and second sidewalls, and wherein electrically insulating the conductive line comprises (a) depositing a thin, conformal layer of a dielectric material onto the first and second sidewalls and a bottom of the trench, and (b) removing the conformal dielectric material from the bottom of the trench to open a line plug and electrically isolate adjacent conductors.
7. The method of claim 1 wherein the trench includes first and second sidewalls, and wherein electrically insulating the conductive line comprises (a) depositing a thin, conformal layer of the dielectric material onto the sidewalls and a bottom of the trench, and (b) removing the conformal dielectric material from the bottom of the trench without a mask layer.
8. The method of claim 1 wherein the conductive line includes a first conductive material, and wherein the method further comprises: depositing a barrier layer in the trench; depositing a second conductive material over the barrier layer to fill the trench; and planarizing the workpiece to remove an overburden portion of the first and second conductive materials relative to the dielectric layer.
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July 27, 2012
January 13, 2015
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